Roller grinding mill



1952 G. JACK ROLLER GRINDING MILL 3 Sheets-Sheet 1 Filed June 9, 1950INVENTOR Y MW" ATTORNEY-6' Aug. 5, 1952 G, JACK 2,606,080

ROLLER GRINDING MILL Filed June 9, 1950 3 Sheets-Sheet 2 L I INVENTOR, lg Mk. /9 B 5%, WW Mn+e0m ATTORNEYS Aug, 5, 1952 k G, JACK 2,606,080

ROLLER GRINDING MILL Filed Jun 9, 1950 5 Sheets-Sheet s r/z ATTORNEYSPatented Aug. 5, 1952 ATENT OFFICE ROLLER. GRINDING MILL George Jack,Rochelle Park, N. .L, assignor to J. M. Lehmann Company, Inc, Lyndhurst,N. .L, a corporation of New York Application June 9, 1950, Serial No.167 ,140

This invention relates vto improvements in grinding mills of the typehaving a plurality of grinding rollers disposed in train with their axesin a single plane and parallel to each other with a feed and grindingroller offset from the plane of the other rolls, usually at one endthereof, and wherein the relative positions of the rollers areadjustable to vary the distance between them and also to change theiroperating pressures in order to adapt the mill for the treatment ofdifferent materials. Generally in a mill of this type, the roller at oneend of the train is journaled in fixed bearings, while the bearings ofall the other rollers in the train as Well as the bearings of the offsetfeed and grinding roller are adjustable in relation thereto. Thus in amill of this type having, for example, a train of four rollers inaddition to the offset feed roller, as many as eight separateadjustments (two for the bearings of each roller) have sometimes beenrequired to adapt the mill for treating a given material.

One of the objects of the present invention is to substantially reducethe number of bearingadjustments in such a mill, by eliminating thenecessity for independently adjusting the positions of the rollersintermediate the top and bottom rollers of the train. Since the separateadjustment of these intermediate rollers requires the exercise of skilland judgment on the part of experienced operators, the elimination ofthe necessity for this saves both time and expense in mill operation.

Another object of the invention is to provide means whereby, once allthe rollers have been adjusted to their desired operating positions andthe mill has completed its run on one batch of material, the rollers ofthe train may be instantly separated to avoid injury to the surfaces ofthe rollers, so that the mill may be cleaned, and in order that therollers may be readily returned to their already adjusted operatingpositions. The utility of the invention in the foregoing and otherrespects will appear more fully from the detailed description thereofwhich follows.

In the accompanying drawings, Figs. 1 and 2 are respectively a top planand a side elevation of a -rol1er mill of the type referred to havingfour grinding rolls or rollers disposed in a ver-- tical train and afeed and grinding roller offset at the bottom of the train; Fig. 3 alarger scale section taken on a plane indicated by the line 33 of Fig.4; and Fig. 4, a front elevation thereof, partly in section and withsome of the parts omitted for better illustration.

The mill shown in the drawings may be driven 6 Claims. (Cl. 308-60) 2 bya motor 10 the shaft of which is belted to a pulley H fast on one of thejournals of the top roller 12 of the vertical train of four rollersthere shown. The bearings for each end of the roller l2, denotedgenerally by the numeral [3, are slidably mounted for verticaladjustment in the respective pairs of frame members l4, l4, one pair ateach end of the mill. Of the other three rollers in the train, thebearings [5 of the bottom roller l6 are permanently fixed, as shown, tothe end frame members I4, I l while the bearings of the intermediaterollers l1 and I8 are slidably mounted for vertical adjustment in theseend frame members, the same as in the case of the bearings of the toproller l2. The bearings of the lowermost roller l9 which is ofiset fromthe train and which, together with the bottom roller 16 of the train,constitute the initial feed and grinding rollers, are mounted in theframe, as shown, for horizontal adjustment toward and from the fixedbearings of the roller it.

The rollers I1, l8, l6 and I9 are driven from roller I2, beingoperatively connected with one of the journals of that roller in suchmanner that roller I! will rotate at slower speed than that of rollerl2, the roller is at slower speed than that of roller l1, the roller l6at slower speed than that of roller 18, and the roller [9 at slowerspeed than that of roller It, so that when'the mill is operated with therollers in their operating positions each will have a rubbing contactwith the adjacent roller or rollers to assist-in reducing the materialunder treatment. This relative difference in the speed of rotation ofadjacent rollers may be brought about by a train of gears, such as shownin Fig. 4, whereof the gears 20, 2|, 22 and 23 are fast on the journalsof the respective rollers l2, l1, l8 and I6 and mesh respectively withlarger gears 24, 25 and 26 fast on the journals of the respectiverollers l1, l8 and I6, and with a gear, which is not shown, on thejournal of the roller l9.

Each bearing [3 of the roller i2 is linked to the bearing next below ofthe intermediate roller l! by a pin 28, and each bearing of roller I1 issimilarly linked to the corresponding bearing ;of the other intermediateroller [8 by a pin 29-. For a purpose presently to be explained each ofthese pins 28, 29 is closely fitted to the lower of the two bearingswhich it connects but has a slight clearance, denoted in Fig. 4 by thenumerals 28' and 29', with the upper of said two bearings.

For adjusting the bearings of the top roller 12 up or down in the framemembers l4, ['4' in order toadjust the position of thatroller-relativeto 3 the fixed bottom roller Hi as well as to the other rollers in thetrain, means controlled by two hand-wheels 30, are provided, onehandwheel for each of the bearings I3. On each said hand-wheel is a worm3| which meshes with a worm-nut 32 threaded to an eyebolt 33 firmlysecured to the adjacent bearing l3 of the top roller. The .shank of'thisboltis'free tomove up and down in the'hollow thrust-head of a ramindicated at 35 and secured to the casing 36 which supports saidadjustin means and is slidable on the mill frame. The nut' 32*bears, atone side, against the thrust-head 34 and, at the other side, against thecasing 36,;so' that when the hand-wheels 30, 3| are turned in onedirection the bearings of the top roller will be moved downwardly tocause that roller'tocontactzand press upon the intermediate roller l'!next below; and when the hand-wheels are turned in'the oppositedirection the pressure between these two *rollers and between the otherrollers of -the columnwillbe"relieved andthe-rollers separated from eachother.

Since the top roller adjusting mechanism just describedis the subject ofa pending patent application filed September 27,1949, Serial Number 1l8,05'l ',now PatentNo. 2,592,048, dated April 8,1952, no claim thereforis made here apart from its use in conjunction with the presentimprovements.

Assum'ing now that therelative positions of the' fourrollers' in thevertical column are such "that=each-saidroller is in working relationwith respect to its adjacent rolleror rollers,-and that the han'd-wheels30,3! are turned in-a direction nekt interrnediate roller I! by apredetermined amount, say of aninch, before the adjusting "movement'ofthe top roller affects said roller H;

"but that by continuing the upward adjusting "movement of the top:roller the intermediate roller 11 -will be caused to separate from thenext intermediate roller I8 by' a predetermined -.amount, sayalso 1% ofaninch; then, by a'still :further upward'adjusting movement of the top-roller, the intermediate roller. I8.will.be caused to separate'fromtheifixed-bottomroller It by a predetermined amountsay again {got aninch. :Hence, when the'top roller has been adjusted :awayffromthefixedbottomroller I6 bya' total of fig lnch; there .will then be aclearance of 1% of an inch between each'of the rollers l'2,' l1, l8andlfi. Conversely, t-whe'n, with-these rollers in "their open orseparated positions, the handiwhe'elsIM, 3 I are tumediin a. directionto-read *Justthe 'mill to its operating condition again awith all' theserollers in working'relation to each other, the uppermost three rollerswill move downward together as a unit until the inter- Jnediate roller[8 assumes its working relation .toithev fixed bottom roller 16 andstops; then the twouppermost rollers will move as'a. unit until theintermediate roller 1'! assumesworking relatlon 'tothe intermediateroller 18 and stops; and

flnally the top roller l2 will move-alone until it assumes workingrelation to the intermediate roller l1. Further adjustment of the toproller toward the fixed bottom roller [6 will now cause pressure to beapplied between the working surfaces of these four rollers, the degreeof which is registered by two pressure gauges 31 (Fig. 2) communicatingrespectively with the cylinders of the rams 35. When these gaugesregister the degree of pressure desired between said rollers for thetreatment of any given material, the mill, so

far as the rollers l2, l1, l8 and i6 are concerned.

is ready for operation upon that material.

It will be understood by those skilled in the art that the adjustment ofthe rolls toward "workingyrelation to each other is carried out when-thesurface of at least one of the rolls is covered with material to betreated, thereby avoiding injury to the roll surface due to thespeed"differential between surfaces which would otherwise be in contact.

Afterthe mill has completed its run onany batch o'f material and itiisdesired to make a new run of .the millon material of a different nature,the mill will ordinarily need to be cleaned to remove all traces of thepreviously treated material. For this purpose it is desirable that therollers be separated sufliciently to make all the parts accessible forthorough cleaning; and where the new run is to be made with the sameroller adjustment as before, it is also desirable that means be providedforinstantly separating the rollers l2, l1, l8 and I6, that is, withoutre- .sort..to the. adjusting meansalready described,

.and then instantly returning them again to their previously adjustedpositions. Accordingly, each bearing l3 of the top rollerlz isprovided.with a rotatablemember '38 carrying a "cam-39 which is embraced by theeye of the bolt '33 aforesaid, so that by apartial rotation of. themembers 38, each of the bearings I3 of the toprrollermay beinstantlyraised, together with the 'bearingsof the intermediaterollers [land I8through their linkage connections with the bearings of the top roller..This will cause'all of the rollers in the'train'to be separated fromeach-other and thusprovide a sufficient-clear- 'ance between them forcleaning. The rotation of .the 'members 38 mayibe effectedby a bellcrank lever dflfulcrumed at 4|. and: connected by links 42. to crankarms 43 respectively provided on the rotatable membersi38. As shown in.Fig. 2, the swinging of this lever through an arc of about degrees fromitsfull line position to its broken-line'position in that figure willcause the instant separation of the. rollers; and 'the swinging'of thislever back to its full line position Willinstantly return the rollersagain to their operating positions without necessitating any readjustingof their relative positions by the hand-wheels 30, 3|.

Theproper adjustment of the offset feeding and grinding roller l9relative to the bottom roller 16 .of the vertical column may be effectedby adjusting means substantially the same as the adjusting meansdescribed aforesaid for the bearings of the top roller l2, and which, asaforesaid, is the subject of the pending patent application filedSeptember 27, 1949, Serial Number 118,057 above mentioned. Thisadjusting means whichis applied to each of the bearings '01 the rollerl9 may be similarly operated by two hand-wheels 45, 45' and will beunderstood without further explanation.

Thus a 5-roller mill of the type shown in the "drawings and which,as-heretoi'ore constructed,

5 sometimes required eight separate roller adjustments to accuratelyposition the rollers for operation, may, in accordance with the presentimprovements, have all its rollers positioned for practical operation byonly four rolleradjustments which are accomplished through the fourhand-wheels aforesaid in the manner above described. In former 5-rollermills built with eight hand-wheels, one pair for each adjustable roller,the manipulation of one pair of hand-wheels to adjust the position ofone of the intermediate rollers of the train will obviously affect thesetting of the adjacent roller or rollers; and it is because of thisthat adjustment of a 5-roller mill as so constructed is extremelydifficult for an inexperienced operator; and great care and goodjudgment have always been necessary to obtain optimum'results fromtheopera-tion of such mills. The present improvements make it possibleto adjust a mill for its best performance in far less time and byoperators who have not had long experience and do not possess the bestof judgment.

In short, the precision of adjustment required for 5-roller milloperation is, so to speak, built into the mill by the incorporation ofthe present improvements, thus leaving only a relatively simple primaryadjustment for the operator.

It may be observed, however, that the use of the improvements thus fardescribed herein would not result in providing substantially equalpressures between the rollers IE, IT, l8 and it when the mill has beenadjusted to its operating condition by the adjustment aforesaid of thetop roller. The reason for this is that the pressur between theintermediate rollers H and 13 would normally exceed the pressure betweenthe top roller and the roller I? by the weight of the roller ii, andthat the pressure between the intermediate roller iii and the bottomroller 18 would normally exceed that between the intermediate rollers l!and it by the weight of the roller It. In the treatment of mostmaterials this pressure differential would not be detrimental to milloperation but in the case of a few materials it might be. Accordingly,the present improvements include means whereby, if desired, thepressures between the different rollers in the vertical column may beequalized. These means consist in the provision of spring supports forbalancing or overcoming the weight of the intermediate rollrs IT and I8respectively. As embodied in the mill shown in the drawings, such springsupports are provided by levers 4B and 4'! fulcrumed to the mill frameat Q6 and M respectively; the upper arms of these levers aresubstantially horizontal and bear directly upon the pins 28 and 29respectively, while their lower arms which are substantially verticalare urged inwardly by compression springs it and 49. These springs areadjustable so as to impart to the pins 25, 29 precisely the amount ofupward pressure required to balance the weight of the respectiveintermediate rollers H and 53. The adjustment of these springs willordinarily be made at the factory; and once adjusted, they require nofurther adjustment or attention by an operator.

The provision of these spring supports has the further advantage thatwhen the top roller is raised or adjusted to release the pressure, thesprings will tend to lift the intermediate rollers i1 and i8 and causeseparation between the rollers l7, l8 and It. In treating some materialsof extremely low viscosity and tackiness, the roller pressure should beaccurately proportioned or set exactly the same between each pair ofrollers.

B I s of his nature, it will be understood that thesprings 48 and 49 maybe so adjusted as to make the intermediate rollers l6 and I?!practically weightless or just floating in operative position.

Bearing in mind that the several rollers are geared to bedriven atdifferent speeds usually at increasing relative speeds from the feedroll through the train to the top roller, it will be apparent to thoseskilled in this art that injury to the roll surfaces may very well takeplace if they are run dry, that is to say, without any treated materialpassing through the mill. If therefore the rolls are not quicklyseparable by throwing'the lever 40 when the supplyof material passingthrough the mill 'is exhausted, injury to the roll surfaces may resultand it is for this reason that the spring supports are valuable inconjunction with the former taking up any lost motion in the latter andmaking it easierto'lift the upper and two intermediate rollers.

In operating the mill shown in the drawings, the material to be treatedis delivered into a hopper 5% (Fig. 2) which feeds the material betweenthe rollers I6 and I9. As these rollers revolve, the material whichpasses between them adheres to the surface thereof and continuallypasses successively from the roller it to each of the rollers above inthe vertical column until it reaches the top roller l2 from the surfaceof which it is scraped by a knife (not shown) .on the inner edge of areceivin pan or discharge chute 5i (Figsl and 2) into which thescrapedoff material drops. This feature of the mill c onstitutes no partof the present invention nor does the water cooling system for therollers, a part of whichis indicated by a pipe 52.

I claim as my invention: 1

1. A roller grinding mill comprising a plurality of rollers disposed oneabove another in a substantially vertical train, a hearing at each endof each roller, frame members at each end of the mill in which all saidbearings but those of the bottom roller of the train are slidable, meansto adjust the position of the top roller of the train relative to thebottom roller of the train, and means to link the slidable bearingstogether comprising pins each of which connects an adjacent pair ofthese bearings and is closely fitted to one of said pair but has aclearance with the other of said pair.

2. A roller grinding mill comprising a plurality of rollers disposed oneabove another in a substantially vertical train, a hearing at each endof each roller, frame members at each end of the mill in which all saidbearings but those of the bottom roller of the train are slidable, meansto adjust the position of the top roller of the train relative to thebottom roller of the train, and means to link the slidable bearingstogether comprising pins each of which connects an adjacent pair ofthese bearings and is closely fitted to the lower bearing of said pairbut has a clearance with the upper bearing of said pair.

3. A roller grinding mill comprising a plurality of rollers disposed oneabove another in a substantially vertical train, a bearing at each endof each roller, frame members at each end of the mill in which all saidbearings but those of the bottom roller of the train are slidable, meansto adjust the position of the top roller of the train relative to thebottom roller of the train, and means to link together respectively theslidable hearings in each end frame member the 76 said last named meanshaving spring supports 7 toibalance respectiVeIy the weights ofeachroller of the train intermediate the top and bottom rollers of.thetrain.

4. A' roller grinding mill comprising a plurality of rollers disposedone above another in a substantially vertical train, a hearing at eachend of each roller; frame members-at each end of the mill 'in' which allsaid bearings but those of the bottom roller of the train are slidable,means to -adjust the position of the top roller of the train relativeto. the bottom roller of the train, and means to link together.respectively the slidable bearings in each end frame member the saidlast named means-having spring supports to balance-respectively theweights of each roller of the train intermediate the top and bottomrollers of the-train, each said spring support comprising a lever, onearm of which is operatively connected to one-of the bearings and aspring applied to the other arm of the lever to impart an upwardpressure of the first named arm.

5. A roller grinding mill comprising a plurality of rollers disposed oneabove another in a substantially vertical train; a hearing at each endof each roller, frame members at each end of the mill in which all saidbearings but those of the bottom roller of the train are slidable; meansto adjust the position of the top roller of the train relative tothe'bottom roller of the train, means to link together respectively theslidable bearings in each end frame member, and spring supports tobalance respectively the weights of each rollerof the train intermediatethe top and bottom rollers ofthe train, and in which the means to linkthe slidable bearings together comprise pins each of which connects oneof the slidable hearings to the slidable bearing next below it, and eachsaid spring support comprising a lever one arm of which contacts one ofthe connecting pins, and a spring applied to the other 8 arm of thelever to impart an upward pressure to. that said pin and through saidpin to the bearing below it.

6. A roller grinding mill comprising a plurality of rollers disposed oneabove another in a. substantially vertical train, a hearing at each endof each roller, frame members at each end of the mill in which all saidbearings but those of the bottom roller of the train are slidable, meansto adjust the position of the top roller of the train relative to thebottom roller of the train, means to link together respectively theslidable bearings in each end frame member, and spring supports tobalance respectively the weights of each roller of the trainintermediate the top and bottom rollers of the train, and in which themeans to link the slidable bearings together comprise pins each of whichconnects one of the slidable bearings to the slidable bearing next belowit, and each pin being closely fitted to the said bearing next below buthaving a clearance with the other said bearing, and each said springsupport comprising a lever one arm of which contacts one of saidconnecting pins. and a spring applied to the other arm of the lever toimpart an upward pressure to said pin and through said pin to the-lowerof the two bearings which it connects.

GEORGE JACK.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS

